Friends and street-safety advocates dedicated a white “ghost bike” to Madison Jane Lyden, the 23-year-old Australian who was riding her bike on Central Park West between 66th and 67th Street when she was hit and killed by a truck driver last month.

Ghost bikes are placed near the sight of a deadly crash to honor the memory of the rider. The bike was draped in an Australian flag, and Lyden’s friends placed photographs on it.